What is Distance
Distance is the actual length of the path travelled by the object.
What is Displacement
Displacement is shortest distance between initial and final position of the object.
Example 1
Distance from Delhi to Mumbai is 1500 km
Distance from Mumbai to Bangalore is 1000 km
Distance from Delhi to Bangalore is 2000 km
Suppose Sanjay goes from Delhi to Mumbai and then from Mumbai to Bangalore
Then what is the Distance and displacement travelled by him
In this Case
Distance Travelled = Distance from Delhi to Mumbai + Distance from Mumbai to Bangalore
= 1000 + 1500
= 2500km
Displacement = Distance from Delhi to Bangalore
=2000 km
Note
Distance travelled by a moving object can never be 0
But Displacement can be 0
Example 2
Suppose a person travels from Delhi to Mumbai for 1500 km
Then he comes back from Mumbai to Delhi traveling another 1500 km
Distance Travelled = Distance from Delhi to Mumbai + Distance from Mumbai to Delhi
=1500 + 1500
= 3000 km
Displacement = 0
(as his Initial Position and Final Position is both Delhi)
Traveling in Circular Path
In this case,Distance can be calculated by using formula for Circumference of Circle
Circumference of Circle = 2 π R
However,Displacement will be 0 if an object completes the full round of the circle.
as on completion of circle,Initial and Final Position is Same.
Example 3
Suppose a person jogs in a park which is circular and completes one round
Diameter of Park is 20 meters
Then what is the Distance and displacement travelled by him
So Radius of Park is 20/2 = 10 m
Distance travelled = 2π×r
= 2 × 22/7 × 10
= 62.85
Displacement = Shortest distance between initial and final point
Since, initial point = final point, displacement = 0.
Note
Distance is a scalar quantity but Displacement is a Vector QuantityScalar Quantity means those quantities which have magnitude.
Vector Quantity means those quantities which have both magnitude and direction.
Example 4
Suppose a person travels from Kashmir to kanyakumari,he travels a distance of 3000 km towards south
Then what is the Distance and displacement travelled by him
In this case,
Distance = 3000 km
Displacement = 3000 Km towards south
Difference between Distance and Displacement
Distance  Displacement 
Distance is the Actual length of the path travelled by the object. 
Displacement is shorterest distance between initial and final position of the object.

It is a scalar quantity.  It is a vector quantity. 
Distance travelled by a body can never be zero.  Displacement travelled by a body can be zero. 
Distance can be positive or zero.  Displacement can be positive, negative or zero. 
How to Find Distance and Displacement if a person travels in Zig Zag Path?
Distance can be found by adding all length travelled
Displacement can be found by connecting starting and ending points with a straight line, the length of the string would give the displacement.
Questions
Q 1 Page 100  An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.
Q 2 Page 100  A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds from his initial position?
Q 3 Page 100 
Which of the following is true for displacement?
(a) It cannot be zero.
(b) Its magnitude is greater than the distance travelled by the object
NCERT Question 1  An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?